The proposed research investigates how children's planning skills develop in social context. Children's planning often involves collaboration with or guidance from other people, which may assist children in developing their planning skills. Guidance from adults and more skilled peers may provide children with models of how to plan and facilitate their participation in skilled planning under supervision. The research investigates the role such social interaction plays in children's development of skills for independent planning, and how children guide adults in their support of children's developing planning skills. The proposed studies focus on how social supports guide children's development of skill in planning and how children make active use of social supports in reaching their goals. The studies examine the processes and effects of planning under adult supervision or in collaboration with adults or peers, and the extent to which planning strategies learned in social interaction generalize to new planning problems. Further studies experimentally model the interactional scripts of adult-child planning, to examine the importance of children's involvement and explicit instruction in strategy use by adults. The studies involve children between 3 and 9 years in spatial planning tasks. A final study examines the rudimentary plans of infants by observing how they use adults instrumentally to reach their goals.